1. Field of the Invention
The present invention relates to an improved method of removing optical components from a blocking tool, which optical components are mounted thereto by means of a low melting alloy, in which said optical components are placed togethcr with their respective blocking tools in a heated liquid bath, in which bath said optical components and their blocking tools are exposed to ultrasonic vibrations in order to deblock said optical components from their respective blocking tools and to remove any mounting material adhering to said optical components and their blocking tools whereupon said optical components, said blocking tools and said mounting material are collected separately.
The present invention relates further to an improved apparatus for removing optical components from a blocking tool, which optical components are mounted thereto by means of a low melting alloy, which apparatus comprises a heated liquid bath and a source of ultrasonic vibrations intended for a deblocking of said optical components from their respective blocking tools and for removing any mounting material from said optical components and blocking tools and comprises further means for separately collecting said optical components, said blocking tools and said removed mounting material, which said apparatus is provided with a tank provided with a heating means; a plurality of ultrasonic transducers mounted to the floor of said tank; a means for holding said optical components which are placed into said tank and a collecting grid intended for collecting deblocked blocking tools.
Before an optical component, for instance, a completely finished and polished lens can be further handled in a cleaning apparatus, such optical component must be deblocked, it must be removed from the blocking tool onto which it has been mounted for allowing above mentioned treatment. This so-called deblocking has hitherto been done manually in that a rim or edge, respectively, area of such optical component projecting beyond its blocking tool is struck against a projection, for instance, the edge of a table, in order to detach the optical component from its blocking tool by such impact treatment. Thereafter, the optical components are cleaned in a cleaning apparatus by the agency of ultrasonic waves and the blocking tools are manually cleaned in a water bath by the agency of a brush. The mounting mass, i.e. the material with which the optical components are mounted, adhered to the blocking tool is collected separately.
Such operation is, however, disadvantageous because the scrap-to-finished product ratio of the optical components is rather high and because the losses of mounting material are extremely high, and the expenditure on work is relatively large.
2. Description of the Prior Art
In the publication "An ultrasonic apparatus for removing optical component blanks from the blocking tool" written by V. G. Zubakov, V. V. Vdovknia, published by the American Institute of Physics, New York, a method for removing optical component blanks from the blocking tool is described, according to which a plurality of optical component blanks which are commonly or separately mounted to a single block are separated and removed from the block or the blocks, respectively, in a tank in which ultrasonic means are located. The removed optical components are collected by a grid. In order to transmit the ultrasonic energy an alcohol-benzene and water-alkali mixtures were used as the work medium in the tank. Thereby a polishing pitch was used as the cementing material. The blocking tools (blocks) consisted of a plastic material. The oscillating means were piezoceramic transducers powered by oscillators which were mounted on the bottom and the walls of the tank. The operating frequency of the transducers was .about.18 kHz.
The method and apparatus disclosed are, however, disadvantageous because a specific solution or mixture, respectively, is utilized as means of transport for the ultrasonic energy and further that the blocking tools which are initially inserted into the tank maintain their position whereby, however, the optical components fall down onto a grid such that they can suffer scratches, and a further disadvantage is that the removed mounting material must be removed from the tank by a separate operating step.